1. The Field of the Invention
The present invention relates to mechanical oscillators. More particularly, the present invention relates to pneumatic oscillators for providing pumping force and controlling the cycle rate of a pump to which the oscillator is connected.
2. The Relevant Technology
Pneumatic oscillators have been utilized for many years as a mechanism to both provide pumping force and to control the rate of oscillation of diaphragm and bellows pumps. The simplistic design of oscillators is well suited for applications requiring low cost, high durability, and continuous operation of the pumping mechanism. Traditional pneumatic oscillators utilize a control valve, such as a spool valve, for controlling air flow and a trip valve for controlling the rate of oscillation of the oscillator. A variety of types and configurations of trip valves and control valves have been developed for a variety of situations and applications. In standard mechanical applications the use of both a control valve and a trip valve adds little additional cost to the overall components of an oscillator.
However, where the marginal cost of the oscillator is particularly important, or where the components of the oscillator are expensive to produce due to design requirements of specialized applications, the cost of each component can be an important consideration in the manufacture of an oscillator. For example, in ultra-pure manufacture settings, the materials and manufacture specifications for pump components can substantially increase the cost of each component utilized. Moreover, in situations in which relatively small pumps are required, the use of oscillators having conventional designs, with both control valves and trip valves, requires more space than is desirable.
Ultra-pure manufacture requirements are utilized in semiconductor and other manufacturing settings where contamination of a pumped fluid can result in the loss of hundreds of thousands or even millions of dollars of product or lost production in a short amount of time. To eliminate the possibility of contamination, pumping components, such as an oscillating valve, are constructed of non-reactive materials to provide the stability, reliability, and corrosion resistance needed to pump the highly reactive materials under extreme temperatures and pressure. The manufacturing challenges presented by typical non-reactive materials can substantially increase the cost of each component utilized.